Throughout the world, particularly in the southeastern United States, there are forest areas that contain locations having the remnants of either past or present sawmill activity. Almost without exception, such locations contain huge concentrations of wood particulate material in the form of sawdust. For all practical purposes, this material is left to rot, its vast storehouse of energy wasted, all because there is no available technology that can cheaply pelletize (compact and densify) the otherwise loose sawdust into cohesive units that can withstand shipment to distant points, storage and ultimate feeding into a combustion chamber. Technology of the type desired contemplates apparatus that can either be stationary or transportable from location to location, wherever the sawdust piles may be found.
Basic to any commercially feasible pelletization operation is that the energy consumed to do the pelletizing, transportation and storage must be much less than the potential combustion energy derived from burning the wood pellets. Most conventional pelletization methods and apparatus presently available require that the wood material be heated during pelletization, using an outside source of heat, so as to render plastic the natural resins in the wood particles. Alternatively, binder materials are added, already heated to a plastic state. Upon cooling, the natural resins or binder material, whichever the case may be, forms a cohesive film that binds one wood particle to another within a pellet. Without an added binder or the activation of the wood's natural resins to a plastic state, wood particles do not satisfactorily adhere or cohere to one another; thus a fragile pellet is formed, not cohesively capable of retaining its shape during subsequent transportation, storage and feeding into a combustion chamber.